Relay and hierarchical transmission scheme

ABSTRACT

In some examples, a method of transmitting data in a radio communication system is described. The method can include dividing data intended for a communication receive node into a high priority code stream and a low priority code stream. The method can also include transmitting the high priority code stream to the communication receive node and a relay node. The method can also include transmitting the low priority code stream to the communication receive node. The relay node may be configured to receive, amplify and forward the high priority code stream to the communication receive node. The communication receive node may be configured to receive the high priority code stream substantially during first time intervals and may be further configured to receive both the low priority code stream and the amplified high priority code stream substantially during second time intervals interleaved with the first time intervals.

BACKGROUND

Unless otherwise indicated herein, the materials described herein arenot prior art to the claims in the present application and are notadmitted to be prior art by inclusion in this section.

At present, radio communication systems are often configured withmultiple base stations and adopt a high coverage broadcast transmissionmode, where each base station independently transmits to user equipmentwithin its proximity. In other words, data transmission typically occursover a single link from the base station to the user equipment. Due tothe wide-spread use of single link transmission, the data transmissionprocess is subject to fading, which may result in mistakes and increaseincidence of user outage. For instance, for user equipment near celledges, large losses during transmission can significantly impairreception performance of the user equipment.

SUMMARY

Techniques described herein generally relate to the hierarchicaltransmission of data in radio communication systems that include one ormore relay nodes.

In some examples, a method of transmitting data in a radio communicationsystem is described. The method can include dividing data intended for acommunication receive node into a high priority code stream and a lowpriority code stream. The method can also include transmitting the highpriority code stream to the communication receive node and a relay node.The method can also include transmitting the low priority code stream tothe communication receive node. The relay node may be configured toreceive, amplify and forward the high priority code stream to thecommunication receive node. The communication receive node may beconfigured to receive the high priority code stream substantially duringfirst time intervals and may be further configured to receive both thelow priority code stream and the amplified high priority code streamsubstantially during second time intervals interleaved with the firsttime intervals.

In some examples, a computer-readable storage medium havingcomputer-executable instructions stored thereon that are executable by acomputing device to perform operations is described. The operations caninclude dividing data intended for a communication receive node into ahigh priority code stream and a low priority code stream. The operationscan also include transmitting the high priority code stream to thecommunication receive node and a relay node. The operations can alsoinclude transmitting the low priority code stream to the communicationreceive node. The relay node may be configured to receive, amplify andforward the high priority code stream to the communication receive node.The communication receive node may be configured to receive the highpriority code stream substantially during first time intervals and maybe further configured to receive both the low priority code stream andthe amplified high priority code stream substantially during second timeintervals interleaved with the first time intervals.

In some examples, a method of receiving data in a radio communicationsystem is described. The method can include receiving, substantiallyduring first time intervals, a high priority code stream from acommunication transmit node. The method can also include receiving,substantially during second time intervals, a low priority code streamfrom the communication transmit node. The method can also includereceiving, substantially during the second time intervals, an amplifiedhigh priority code stream from a relay node.

In some examples, a computer-readable storage medium havingcomputer-executable instructions stored thereon that are executable by acomputing device to perform operations is described. The operations caninclude receiving, substantially during first time intervals, a highpriority code stream from a communication transmit node. The operationscan also include receiving, substantially during second time intervals,a low priority code stream from the communication transmit node. Theoperations can also include receiving, substantially during the secondtime intervals, an amplified high priority code stream from a relaynode.

In some examples, a radio communication system is described that caninclude a communication transmit node, a relay node, and a communicationreceive node. The communication transmit node can be configured todivide data into a high priority code stream and a low priority codestream and to transmit the high priority and low priority code streams.The relay node can be configured to receive, amplify and forward thehigh priority code stream. The communication receive node can beconfigured to receive the high priority code stream from thecommunication transmit node substantially during first time intervals,to receive the low priority code stream from the communication transmitnode substantially during second time intervals, and to receive theamplified high priority code stream from the relay node substantiallyduring the second time intervals.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE FIGURES

In the drawings:

FIG. 1 is a diagram of a radio communication system including acommunication transmit node, a relay node, and a communication receivenode;

FIG. 2 is a schematic diagram of data transmitted and received in theradio communication system of FIG. 1;

FIG. 3 is a block diagram of an example embodiment of the communicationtransmit node and the communication receive node of FIG. 1;

FIG. 4 shows an example flow diagram of a method of transmitting data ina radio communication system;

FIG. 5 shows an example flow diagram of a method of receiving data in aradio communication system;

FIG. 6 is a graph comparing capacity between various radio communicationsystems; and

FIG. 7 is a graph comparing incidence of outage between various radiocommunication systems,

all arranged in accordance with at least some embodiments describedherein.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols typically identify similar components, unless contextdictates otherwise. The illustrative embodiments described in thedetailed description, drawings, and claims are not meant to be limiting.Other embodiments may be utilized, and other changes may be made,without departing from the spirit or scope of the subject matterpresented herein. It will be readily understood that the aspects of thepresent disclosure, as generally described herein, and illustrated inthe Figures, can be arranged, substituted, combined, separated, anddesigned in a wide variety of different configurations, all of which areexplicitly contemplated herein.

Some embodiments disclosed herein generally relate to techniques forhierarchically transmitting data in a radio communication system thatincludes one or more relay nodes. Generally, for example, data intendedfor a communication receive node, such as a mobile phone, smart phone,or laptop computer, may be divided into a high priority code stream anda low priority code stream by a communication transmit node, such as abase station or an evolved Node B (eNB). Both code streams may betransmitted to the communication receive node such that data from thehigh priority code stream is transmitted during first time intervals anddata from the low priority code stream is transmitted during second timeintervals interleaved with the first time intervals.

The high priority code stream may be received by both the communicationreceive node and a relay node during the first time intervals. The relaynode may be synchronized with the communication transmit node and may beconfigured to amplify and forward the high priority code stream to thecommunication receive node during the second time intervals. Thus,during the second time intervals, the communication receive node mayreceive both the low priority code stream from the communicationtransmit node and the amplified high priority code stream from the relaynode.

The high priority code stream may be configured to ensure basiccommunication service for the communication receive node. The lowpriority code stream may be configured to enhance communication servicefor the communication receive node. Receiving the high priority codestream during the first time intervals and the amplified high prioritycode stream during the second time intervals provides time diversity fordata included in the high priority code stream, which may improveperformance in the radio communication system. Accordingly, in the eventthe communication receive node receives only the high priority codestream and/or the amplified high priority code stream, the communicationreceive node may still have basic communication service in the radiocommunication system. In the event the communication receive nodeadditionally receives the low priority code stream, the communicationservice to the communication receive node may be improved, therebyimproving a user experience of a user associated with the communicationreceive node.

The techniques described herein may be used for various radiocommunication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and othersystems. The terms “system” and “network” are often usedinterchangeably. A CDMA system may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. cdma2000 coversIS-2000, IS-95 and IS-856 standards. A TDMA system may implement a radiotechnology such as Global System for Mobile Communications (GSM). AnOFDMA system may implement a radio technology such as Evolved UTRA(E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDM (R), etc. UTRA and E-UTRA are part ofUniversal Mobile Telecommunication System (UMTS). 3GPP Long TermEvolution (LTE) is a release of UMTS that uses E-UTRA, which employsOFDMA on the downlink and SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTEand GSM are described in documents from an organization named “3rdGeneration Partnership Project” (3GPP). cdma2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2).

FIG. 1 is a diagram of a radio communication system 100 including acommunication transmit node 102, a relay node 104, and a communicationreceive node 106, arranged in accordance with at least some embodimentsdescribed herein. In the illustrated embodiment, the radio communicationsystem 100 is implemented as a single “cell” serviced by thecommunication transmit node 102. More generally, the radio communicationsystem 100 may include a multiple number of cells, each of which may beserviced by a corresponding communication transmit node 102. In theseand other embodiments, the communication transmit node 102 may beimplemented as, e.g., a base station, an eNB, or the like.

In some embodiments, the communication transmit node 102 may beconfigured to divide data intended for the communication receive node106 into two code streams, including a high priority code stream 108 anda low priority code stream 110. The data intended for the communicationreceive node 106 may include, e.g., video data, voice data, or otherdata. In general, the data in the high priority code stream 108 may beconfigured to facilitate successful access of the radio communicationsystem 100 and basic communication with the radio communication system100 by the communication receive node 106, while data in the lowpriority code stream 110 may be configured to provide enhancedcommunication with the radio communication system 100.

Although not required, in some embodiments, the low priority code stream110 has a lower data flow rate than the high priority code stream 108.For instance, over time, about 11/16 of the data intended for thecommunication receive node 106 may be transmitted through the highpriority code stream 108, while about 5/16 of the data intended for thecommunication receive node 106 may be transmitted through the lowpriority code stream 108.

Optionally, the data intended for the communication receive node 106 mayinclude video data coded using a layered video coding scheme such thatthe coded video data includes, e.g., a base layer and an enhancementlayer. In these and other embodiments, the high priority code stream 108may include, for instance, control information and the base layer of thecoded video data. The control information may facilitate successfulaccess of the radio communication system 100 by the communicationreceive node 106, while the base layer of the video data may providebasic video quality. Alternately or additionally, the low priority codestream 110 may include, for instance, the enhancement layer of the codedvideo data. By combining the base layer of the coded video data with theenhancement layer of the coded video data, the communication receivenode 106 may provide higher quality video than would otherwise bepossible using solely the base layer of the coded video data.

In some embodiments, the communication transmit node 102 may beconfigured to interleave, in an alternating fashion, data included inthe high priority code stream 108 with data included in the low prioritycode stream 110 in time slots of equal or different lengths. Time slotsduring which data from the high priority code stream 108 is transmittedmay be referred to hereinafter as “first time intervals,” while timeslots during which data from the low priority code stream 110 istransmitted may be referred to hereinafter as “second time intervals.” A“transmission process” as used hereinafter may refer to a transmissionby the communication transmit node 102 that spans a first time intervaland an immediately subsequent second time interval.

In general, the relay node 104 may be configured to receive atransmission of data from an upstream station, e.g., from thecommunication transmit node 102, and to send a transmission of data to adownstream station, e.g., to the communication receive node 106. Inthese and other embodiments, the relay node 104 may alternate between areceive mode and an amplify-and-forward mode. The receive mode may besynchronized with the first time intervals and the amplify-and-forwardmode may be synchronized with the second time intervals. For instance,in the receive mode, the relay node 104 may be configured to receive thehigh priority code stream 108 during the first time interval of eachtransmission process of the communication transmit node 102. Alternatelyor additionally, in the amplify-and-forward mode, the relay node 104 maybe configured to amplify and forward the high priority code stream 108to the communication receive node 106 during the second time interval ofeach transmission process. The amplified high priority code stream 108forwarded to the communication receive node 106 by the relay node 104during the second time interval of each transmission process isidentified in FIG. 1 at 112, and is referred to hereinafter as the“amplified high priority code stream 112.”

The communication receive node 106 may be referred to as a terminal, anaccess terminal (AT), a mobile station (MS), user equipment (UE), asubscriber unit, station, or the like. In some embodiments, thecommunication receive node 106 may include, but is not limited to amobile phone, a smartphone, a laptop computer, or the like or anycombination thereof.

The communication receive node 106 may communicate with thecommunication transmit node 102 via a downlink (e.g., high and lowpriority code streams 108, 110 and/or amplified high priority codestream 112) and/or an uplink (not shown). The downlink (or forward link)refers to the communication link from the communication transmit node102 to the communication receive node 106, and the uplink (or reverselink) refers to the communication link from the communication receivenode 106 to the communication transmit node 102.

The communication receive node 106 is generally configured to receivedata transmitted to the communication receive node 106 by either or bothof the communication transmit node 102 or the relay node 104. In someembodiments, for instance, the communication receive node 106 isconfigured to receive data included in the high priority code stream 108and/or the low priority code stream 110 from the communication transmitnode 102. In these and other embodiments, the communication receive node106 may receive, substantially during the first time intervals, the highpriority code stream 108 and may additionally receive, substantiallyduring the second time intervals, the low priority code stream 110.

Alternately or additionally, the communication receive node 106 may beconfigured to receive data included in the amplified high priority codestream 112 from the relay node 104. In these and other embodiments, thecommunication receive node 106 may receive, substantially during thesecond time interval(s), the amplified high priority code stream 112.Thus, the communication receive node 106 may be configured to receive,substantially during the second time interval(s), the low priority codestream 110 from the communication transmit node 102 and the amplifiedhigh priority code stream 112 from the relay node 104 since both may betransmitted to the communication receive node 106 during the second timeintervals according to some embodiments.

Alternately or additionally, the communication receive node 106 may beconfigured to separate the amplified high priority code stream 112 fromthe low priority code stream 110. For example, the communication receivenode 106 may perform a minimum mean squared error analysis of the lowpriority code stream 110 and the amplified high priority code stream 112which are both received substantially during the second time intervalsto separate the amplified high priority code stream 112 from the lowpriority code stream 110.

FIG. 2 is a schematic diagram of data 200 transmitted and received inthe radio communication system 100 of FIG. 1, arranged in accordancewith at least some embodiments described herein. With combined referenceto FIGS. 1-2, the data 200 may include first data 200A associated withthe communication transmit node 102, second data 200B associated withthe relay node 104, and third data 200C associated with thecommunication receive node 106.

In more detail, the first data 200A associated with the communicationtransmit node 102 may include high priority data X₁ included in the highpriority code stream 108, and low priority data X₂ included in the lowpriority code stream 110. The high priority data X₁ may be transmittedby the communication transmit node 102 during the first time intervalsand may have a duration t. The low priority data X₂ may be transmittedby the communication transmit node 102 during the second time intervals,and may also have a duration t. The first time intervals are identifiedin FIG. 2 at 202, and the second time intervals are identified in FIG. 2at 204.

The second data 200B associated with the relay node 104 may include highpriority data X_(1-R1) received from the communication transmit node 102in the high priority code stream 108 during the first time intervals202, and amplified high priority data X_(1-A) transmitted to thecommunication receive node 106 in the amplified high priority codestream 112 during the second time intervals 204. In some embodiments,each block of amplified high priority data X_(1-A) transmitted to thecommunication receive node 106 in the amplified high priority codestream 112 during a second time interval 204 may include an amplifiedversion of the corresponding block of high priority data X_(1-R1)received from the communication transmit node 102 during an immediatelypreceding first time interval 202.

The third data 200C associated with the communication receive node 106may include high priority data X_(1-R2) received from the communicationtransmit node 102 in the high priority code stream 108 during the firsttime intervals 202. During the second time intervals 204, however, thecommunication receive node 106 may receive one or both of amplified highpriority data X_(1-AR) from the relay node 104 in the amplified highpriority code stream 112 and low priority data X_(2-R) from thecommunication transmit node 102 in the low priority code stream 110. Insome embodiments, receiving, at the communication receive node 106, highpriority data X_(1-R2) of the high priority code stream 108 during thefirst time intervals 202 and amplified high priority data X_(1-AR) ofthe amplified high priority code stream 112 during the second timeintervals 204 provides time diversity with respect to the originallytransmitted high priority data X₁, which may improve receptionperformance of the original transmitted high priority data X₁ byeliminating or minimizing error bursts, for instance.

FIG. 3 is a block diagram of an example embodiment of the communicationtransmit node 102 and the communication receive node 106 of FIG. 1,arranged in accordance with at least some embodiments described herein.

In the illustrated embodiment, the communication transmit node 102 mayinclude, for example, a data source 302, a transmit (TX) data processor304, a TX multiple input multiple output (MIMO) processor 306, one ormore transceivers 308A-308N, one or more antennas 310A-310N, a processor312, a memory or other computer-readable storage medium 314, a receive(RX) data processor 316, and a demodulator 318. Each of the transceivers308A-308N may include a transmitter (TMTR) and a receiver (RCVR).

Alternately or additionally, the communication receive node 106 mayinclude, for example, a data source 320, a TX data processor 322, amodulator 324, one or more transceivers 326A-326N, one or more antennas328A-328N, a processor 330, a memory or other computer-readable storagemedium 332, and an RX data processor 334. Each of the transceivers326A-326N may include a transmitter (TMTR) and a receiver (RCVR).

An example embodiment of operation of the components of thecommunication transmit node 102 and the communication receive node 106that are depicted in FIG. 3 will now be described. At the communicationtransmit node 102, traffic data for a number of data streams may beprovided from the data source 302 to the TX data processor 304. The TXdata processor 304 may format, code, and interleave the traffic data foreach data stream based on a particular coding scheme selected for thatdata stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot datausing OFDM techniques. The pilot data may include a known data patternthat is processed in a known manner and that may be used at a receiversystem to estimate channel response. The multiplexed pilot and codeddata for each data stream may then be modulated (i.e., symbol mapped)based on a particular modulation scheme (e.g., BPSK, QSPK, M-PSK, orM-QAM) selected for that data stream to provide modulation symbols.

The data rate, coding, and modulation for each data stream may bedetermined by the processor 312 executing computer-executableinstructions stored on the memory 314. Alternately or additionally, theprocessor 312 may execute computer-executable instructions stored on thememory 314 or other location that are effective to cause thecommunication transmit node 102 to perform one or more of the operationsdescribed herein. The memory 314 may store computer-executableinstructions such as program code, as well as data, and/or otherinformation used by the processor 312 or other components of thecommunication transmit node 102.

The modulation symbols for all data streams may then be provided to theTX MIMO processor 306, which may further process the modulation symbols(e.g., for OFDM). The TX MIMO processor 306 may then provide modulationsymbol streams to transceivers 308A-308N. In some embodiments, the TXMIMO processor 306 may apply beam-forming weights to the symbols of thedata streams and/or to the antenna 310A-310N from which the symbol isbeing transmitted.

Each transceiver 308A-308N may receive and process a respective symbolstream to provide one or more analog signals, and may further condition(e.g., amplify, filter, and/or upconvert) the analog signals to providea modulated signal suitable for transmission over the MIMO channel.Modulated signals from transceivers 308A-308N are then transmitted fromantennas 310A-310N, respectively.

At the communication receive node 106, the transmitted modulated signalsmay be received by antennas 328A-328N and the received signal from eachantenna 328A328N may be provided to a respective transceiver 326A-326N.Each transceiver 326A-326N may condition (e.g., filter, amplify, anddownconvert) a respective received signal, digitize the conditionedsignal to provide samples, and further process the samples to provide acorresponding “received” symbol stream.

The RX data processor 334 may then receive and process the receivedsymbol streams from the transceivers 326A-326N based on a particularreceiver processing technique to provide “detected” symbol streams. TheRX data processor 334 may then demodulate, deinterleave, and decode eachdetected symbol stream to recover the traffic data for the data stream.The processing by the RX data processor 334 may be complementary to thatperformed by the TX MIMO processor 306 and the TX data processor 304 atthe communication transmit node 102.

The processor 330 may periodically determine which pre-coding matrix touse. The processor 330 may formulate a reverse link message comprising amatrix index portion and a rank value portion. Alternately oradditionally, the processor 330 may execute computer-executableinstructions stored on the memory 332 or other location that areeffective to cause the communication receive node 106 to perform one ormore of the operations described herein. The memory 332 may storecomputer executable instructions such as program code, as well as dataand/or other information used by the processor 312 or other componentsof the communication receive node 106.

Reverse link messages may be generated by the communication receive node106 and may include various types of information regarding thecommunication link between the communication receive node 106 and thecommunication transmit node 102, and/or regarding the received datastream. Reverse link messages may be processed by the TX data processor322, which may also receive traffic data for one or more data streamsfrom the data source 320, modulated by the modulator 324, conditioned bythe transceivers 326A-326N, and transmitted back to the communicationtransmit node 102.

At the communication transmit node 102, the modulated signals from thecommunication receive node 106 may be received by the antennas310A-310N, conditioned by the transceivers 308A-308N, demodulated by thedemodulator 318, and processed by the RX data processor 316 to extractreverse link messages transmitted by the communication receive node 106.The processor 312 may then determine which pre-coding matrix to use fordetermining the beam-forming weights and/or may then process theextracted message.

FIG. 4 shows an example flow diagram of a method 400 of transmittingdata in a radio communication system, arranged in accordance with atleast some embodiments described herein. The method 400 may be performedin whole or in part by, e.g., the communication transmit node 102 in theradio communication system 100 of FIG. 1. The method 400 includesvarious operations, functions or actions as illustrated by one or moreof blocks 402, 404 and/or 406. The method 400 may begin at block 402.

In block 402, [“Divide Data Intended For A Communication Receive NodeInto A High Priority Code Stream And A Low Priority Code Stream”], dataintended for a communication receive node, such as the communicationreceive node 106 of FIG. 1, is divided into a high priority code streamand a low priority code stream, such as the high and low priority codestreams 108, 110 of FIG. 1. The data may be divided between the highpriority code stream and low priority code stream based on a relativeimportance of the data. For example, video data coded using a layeredvideo coding scheme may include a base layer and an enhancement layer.The base layer may be considered to be relatively more important thanthe enhancement layer in some embodiments, and thus the base layer maybe included in the high priority code stream while the enhancement layermay be included in the low priority code stream.

Data included in the high priority code stream and the low priority codestream may be coded. In these and other embodiments, the coding of thedata in the high priority code stream and the low priority code streammay be the same or it may be different. Alternately or additionally, thehigh priority code stream may be configured to ensure basiccommunication service for the communication receive node, while the lowpriority code stream may be configured to enhance communication servicefor the communication receive node. Block 402 may be followed by block404.

In block 404, [“Transmit The High Priority Code Stream To TheCommunication Receive Node And A Relay Node”], the high priority codestream may be transmitted to the communication receive node and a relaynode. In these and other embodiments, the relay node may be configuredto receive, amplify and forward the high priority code stream to thecommunication receive node. Alternately or additionally, thecommunication receive node may be configured to receive the highpriority code stream substantially during first time intervals and maybe further configured to receive both the low priority code stream andthe amplified high priority code stream substantially during second timeintervals interleaved with the first time intervals. Alternately oradditionally, transmitting the high priority code stream to thecommunication receive node and a relay node may include transmittingdata included in the high priority code stream during the first timeintervals. Block 404 may be followed by block 406.

In block 406, [“Transmit The Low Priority Code Stream To TheCommunication Receive Node”], the low priority code stream may betransmitted to the communication receive node. Transmitting the lowpriority code stream to the communication receive node may includetransmitting data included in the low priority code stream during thesecond time intervals.

Some embodiments disclosed herein include a computer-readable storagemedium having computer-executable instructions stored thereon that areexecutable by a computing device to perform operations included in themethod 400 of FIG. 4, such as the operations illustrated by blocks 402,404, and/or 406 in FIG. 4. In these and other embodiments, the computingdevice may be included in the communication transmit node. For instance,the computing device may include the processor 312 included in thecommunication transmit node 102 of FIG. 3. Alternately or additionally,the computer-readable storage medium may include the memory 314 includedin the communication transmit node 102 of FIG. 3.

One skilled in the art will appreciate that, for this and otherprocesses and methods disclosed herein, the functions performed in theprocesses and methods may be implemented in differing order.Furthermore, the outlined steps and operations are only provided asexamples, and some of the steps and operations may be optional, combinedinto fewer steps and operations, or expanded into additional steps andoperations without detracting from the essence of the disclosedembodiments.

For example, block 406 in which the low priority code stream istransmitted to the communication receive node may be omitted to reducedata traffic in the radio communication system. Reducing data trafficmay be desirable during periods of heavy demand for system resources inthe radio communication system, during periods of reduced resourceavailability, and/or at other times. In these and other embodiments, thehigh priority code stream transmitted to the communication receive nodeand forwarded by the relay node to the communication receive node canensure basic communication service for the communication receive node,while demand for system resources may be reduced by not transmitting thelow priority code stream.

FIG. 5 shows an example flow diagram of a method 500 of receiving datain a radio communication system, arranged in accordance with at leastsome embodiments described herein. The method 500 may be performed inwhole or in part by, e.g., the communication receive node 106 in theradio communication system 100 of FIG. 1. The method 500 includesvarious operations, functions or actions as illustrated by one or moreof blocks 502, 504, 506. The method 500 may begin at block 502.

In block 502, [“Receive, Substantially During First Time Intervals, AHigh Priority Code Stream From A Communication Transmit Node”], a highpriority code stream from a communication transmit node is receivedsubstantially during first time intervals. The first time intervals maycorrespond to the first time intervals 202 of FIG. 2, for instance. Thehigh priority code stream may be configured to ensure basiccommunication service for a communication receive node that receives thehigh priority code stream. Block 502 may be followed by block 504.

In block 504, [“Receive, Substantially During Second Time Intervals, ALow Priority Code Stream From The Communication Transmit Node”], a lowpriority code stream from the communication transmit node may bereceived substantially during second time intervals. The second timeintervals may correspond to the second time intervals 204 of FIG. 2, forinstance. The low priority code stream may be configured to enhancecommunication service for the communication receive node relative toreception quality when only the high priority code stream is received.Block 504 may be followed by block 506.

In block 506, [“Receive, Substantially During The Second Time Intervals,An Amplified High Priority Code Stream From A Relay Node”], an amplifiedhigh priority code stream from a relay node may be receivedsubstantially during the second time intervals. In some embodiments,receiving both the high priority code stream during the first timeintervals and an amplified high priority code stream during the secondtime intervals provides time diversity for data included in the highpriority code stream. The communication receive node may take advantageof the time diversity to minimize or reduce error bursts, for instance,and thereby improve reception performance.

The method 500 may be modified to include more or fewer steps thanillustrated in FIG. 5. For example, block 504 in which the low prioritycode stream is received from the communication transmit node may beomitted if, for instance, the communication transmit node does nottransmit the low priority code stream or if the communication receivenode is otherwise unable to receive the low priority code stream. Asdescribed above with respect to FIG. 4, the communication transmit nodemay determine not to transmit the low priority code stream duringperiods of heavy demand for system resources, during periods of reducedresource availability, or the like. In these and other embodiments, thehigh priority code stream received from the communication transmit nodeand the amplified high priority code stream received from the relay nodemay ensure basic communication service for the communication receivenode even in the absence of the low priority code stream.

As another example, the method 500 may further include separating theamplified high priority code stream from the low priority code stream.Separating the amplified high priority code stream from the low prioritycode stream may include performing a minimum means squared erroranalysis of the received low priority code stream and the amplified highpriority code stream.

As yet another example, the method 500 may further include combining thelow priority code stream and the high priority code stream together forimproved service quality. The low priority code stream and the highpriority code stream may be combined using a particular decoder, such asa layered video decoder in embodiments where the data in the highpriority code stream and low priority code stream includes video data.

Some embodiments disclosed herein include a computer-readable storagemedium having computer-executable instructions stored thereon that areexecutable by a computing device to perform operations included in themethod 500 of FIG. 5, such as the operations illustrated by blocks 502,504, and/or 506 in FIG. 5. In these and other embodiments, the computingdevice may be included in the communication receive node. For instance,the computing device may include the processor 330 included in thecommunication receive node 106 of FIG. 3. Alternately or additionally,the computer-readable storage medium may include the memory 332 includedin the communication receive node 106 of FIG. 3.

FIG. 6 is a graph comparing capacity between various radio communicationsystems, arranged in accordance with at least some embodiments describedherein. FIG. 6 includes a first curve 602 and a second curve 604. Thefirst curve 602 may represent simulated capacity as a function ofdistance D (in kilometers (km)) in a first radio communication system.The first radio communication system may generally be configured asillustrated in FIG. 1, and may include a communication transmit node, arelay node, and a communication receive node, all generally configuredas described hereinabove. The distance D may refer to the distance fromthe communication transmit node to the communication receive node. Table1 below presents various simulation parameters used in the simulation ofthe first curve 602.

TABLE 1 System Bandwidth 8 MHz Frequency Point 740 MHz Cell Radius r = 2km Distance Between 0.5*r = 1 km    Communication Transmit Node AndRelay Node Path Loss Model PL = 15 + 30logD (D in km) CommunicationTransmit 35 dBm Node Transmit Power Relay Node Transmit Power 20 dBmInterference Power 5 dBm Signal to Noise Ratio 18 dB CommunicationTransmit 4096 Node-Relay Node Link Signal To Noise Ratio Number ofSubcarriers 3076 Channel Communication Chinese 6 Type Transmit Node-Communication Receive Node, Relay Node- Communication Receive NodeCommunication Single-Path Rayleigh Transmit Node- Channel Relay Node

The second curve 604 may represent simulated capacity as a function ofthe distance D in a second radio communication system. The second radiocommunication system may include a communication transmit node and acommunication receive node without a relay node. Additionally, thesecond radio communication system may implement a standard high coveragebroadcast mode often employed in radio communication systems in theabsence of relay nodes.

As seen in FIG. 6 by comparing the first and second curves 602, 604, thecapacity of the first and second radio communication systems issubstantially the same from D=0 km to about D=1.15 km. However, fromabout D=1.15 km to about D=2 km, the capacity of the first radiocommunication system including a relay node and generally configured asdisclosed herein is significantly improved compared to the capacity ofthe second radio communication system lacking a relay node.

FIG. 7 is a graph comparing incidence of outage between various radiocommunication systems, arranged in accordance with at least someembodiments. FIG. 7 includes a first curve 702, a second curve 704, anda third curve 706. The first curve 702 may represent simulated outage asa function of distance D (in km) for a high priority code stream in thefirst radio communication system described with respect to FIG. 6. Thesecond curve 704 may represent simulated outage as a function ofdistance D for a low priority code stream in the first radiocommunication system. The third curve 706 may represent simulated outageas a function of distance D for a standard transmission stream in thesecond radio communication system described with respect to FIG. 6.

As seen in FIG. 7 by comparing the first, second and third curves 702,704, 706, the outage of the high priority code stream (first curve 702)is significantly less than the outage of the standard transmissionstream (third curve 706) from about 1 km to about 2 km. Additionally,the outage of the low priority code stream (second curve 704) issignificantly less than the outage of the standard transmission streamfrom about 1.25 km to about 2 km.

It can be seen from FIGS. 6 and 7 that some embodiments described hereinmay improve radio communication system performance, such as by improvingsystem capacity or by decreasing incidence of user outage, or byotherwise improving performance. Alternately or additionally, someembodiments described herein may be implemented in existing radiocommunication systems by adding low-cost relay nodes to the radiocommunication system and implementing a hierarchical transmissionscheme. Accordingly, some embodiments described herein may permitoperators of radio communication systems to efficiently and flexiblyexpand coverage of radio systems and to raise user experience withrespect to the systems to thereby enlarge customer scale and increasebusiness profits.

The present disclosure is not to be limited in terms of the particularembodiments described herein, which are intended as illustrations ofvarious aspects. Many modifications and variations can be made withoutdeparting from its spirit and scope, as will be apparent to thoseskilled in the art. Functionally equivalent methods and apparatuseswithin the scope of the disclosure, in addition to those enumeratedherein, will be apparent to those skilled in the art from the foregoingdescriptions. Such modifications and variations are intended to fallwithin the scope of the appended claims. The present disclosure is to belimited only by the terms of the appended claims, along with the fullscope of equivalents to which such claims are entitled. It is to beunderstood that the present disclosure is not limited to particularmethods, reagents, compounds compositions or biological systems, whichcan, of course, vary. It is also to be understood that the terminologyused herein is for the purpose of describing particular embodimentsonly, and is not intended to be limiting.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity.

It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to embodiments containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should be interpreted to mean “at least one”or “one or more”); the same holds true for the use of definite articlesused to introduce claim recitations. In addition, even if a specificnumber of an introduced claim recitation is explicitly recited, thoseskilled in the art will recognize that such recitation should beinterpreted to mean at least the recited number (e.g., the barerecitation of “two recitations,” without other modifiers, means at leasttwo recitations, or two or more recitations). Furthermore, in thoseinstances where a convention analogous to “at least one of A, B, and C,etc.” is used, in general such a construction is intended in the senseone having skill in the art would understand the convention (e.g., “asystem having at least one of A, B, and C” would include but not belimited to systems that have A alone, B alone, C alone, A and Btogether, A and C together, B and C together, and/or A, B, and Ctogether, etc.). In those instances where a convention analogous to “atleast one of A, B, or C, etc.” is used, in general such a constructionis intended in the sense one having skill in the art would understandthe convention (e.g., “a system having at least one of A, B, or C” wouldinclude but not be limited to systems that have A alone, B alone, Calone, A and B together, A and C together, B and C together, and/or A,B, and C together, etc.). It will be further understood by those withinthe art that virtually any disjunctive word and/or phrase presenting twoor more alternative terms, whether in the description, claims, ordrawings, should be understood to contemplate the possibilities ofincluding one of the terms, either of the terms, or both terms. Forexample, the phrase “A or B” will be understood to include thepossibilities of “A” or “B” or “A and B.”

In addition, where features or aspects of the disclosure are describedin terms of Markush groups, those skilled in the art will recognize thatthe disclosure is also thereby described in terms of any individualmember or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and allpurposes, such as in terms of providing a written description, allranges disclosed herein also encompass any and all possible sub rangesand combinations of sub ranges thereof. Any listed range can be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein canbe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” and the like include the number recited andrefer to ranges which can be subsequently broken down into sub ranges asdiscussed above. Finally, as will be understood by one skilled in theart, a range includes each individual member. Thus, for example, a grouphaving 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, agroup having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells,and so forth.

From the foregoing, it will be appreciated that various embodiments ofthe present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure.Accordingly, the various embodiments disclosed herein are not intendedto be limiting, with the true scope and spirit being indicated by thefollowing claims.

1. A method of transmitting data in a radio communication system, themethod comprising: dividing data intended for a communication receivenode into a high priority code stream and a low priority code stream;transmitting the high priority code stream to the communication receivenode and a relay node; and transmitting the low priority code stream tothe communication receive node; wherein: the relay node is configured toreceive, amplify and forward the high priority code stream to thecommunication receive node; and the communication receive node isconfigured to receive the high priority code stream substantially duringfirst time intervals and is further configured to receive both the lowpriority code stream and the amplified high priority code streamsubstantially during second time intervals interleaved with the firsttime intervals.
 2. The method of claim 1, wherein the data is dividedinto the high priority and low priority code streams and the highpriority and low priority code streams are transmitted by acommunication transmit node.
 3. The method of claim 1, wherein the highpriority code stream is configured to ensure basic communication servicefor the communication receive node.
 4. The method of claim 3, whereinthe low priority code stream is configured to enhance communicationservice for the communication receive node.
 5. The method of claim 1,wherein: transmitting the high priority code stream to the communicationreceive node and a relay node includes transmitting data included in thehigh priority code stream during the first time intervals; andtransmitting the low priority code stream to the communication receivenode includes transmitting data included in the low priority code streamduring the second time intervals.
 6. A computer-readable storage mediumhaving computer-executable instructions stored thereon that areexecutable by a computing device to perform operations comprising:dividing data intended for a communication receive node into a highpriority code stream and a low priority code stream; transmitting thehigh priority code stream to the communication receive node and a relaynode; and transmitting the low priority code stream to the communicationreceive node; wherein: the relay node is configured to amplify andforward the high priority code stream to the communication receive node;and the communication receive node is configured to receive the highpriority code stream substantially during first time intervals and isfurther configured to receive both the low priority code stream and theamplified high priority code stream substantially during second timeintervals interleaved with the first time intervals.
 7. Thecomputer-readable storage medium of claim 6, wherein the computingdevice is included in a communication transmit node.
 8. Thecomputer-readable storage medium of claim 7, wherein the communicationtransmit node comprises a base station or an evolved Node B.
 9. Thecomputer-readable storage medium of claim 6, wherein the high prioritycode stream is configured to ensure basic communication service for thecommunication receive node.
 10. The computer-readable storage medium ofclaim 6, wherein the low priority code stream is configured to enhancecommunication service for the communication receive node.
 11. Thecomputer-readable storage medium of claim 6, wherein: transmitting thehigh priority code stream to the communication receive node and a relaynode includes transmitting data included in the high priority codestream during the first time intervals; and transmitting the lowpriority code stream to the communication receive node includestransmitting data included in the low priority code stream during thesecond time intervals.
 12. A method of receiving data in a radiocommunication system, the method comprising: receiving, substantiallyduring first time intervals, a high priority code stream from acommunication transmit node; receiving, substantially during second timeintervals, a low priority code stream from the communication transmitnode; and receiving, substantially during the second time intervals, anamplified high priority code stream from a relay node.
 13. The method ofclaim 12, further comprising separating the amplified high priority codestream from the low priority code stream.
 14. The method of claim 13,wherein separating the amplified high priority code stream from the lowpriority code stream includes performing a minimum mean squared erroranalysis of the received low priority code stream and the amplified highpriority code stream.
 15. The method of claim 12, wherein the highpriority code stream is configured to ensure basic communication servicefor a communication receive node that receives the high priority codestream.
 16. The method of claim 15, wherein the low priority code streamis configured to enhance communication service for the communicationreceive node.
 17. The method of claim 12, wherein receiving the highpriority code stream substantially during the first time intervals andan amplified high priority code stream substantially during the secondtime intervals provides time diversity for data included in the highpriority code stream.
 18. A computer-readable storage medium havingcomputer-executable instructions stored thereon that are executable by acomputing device to perform operations comprising: receiving,substantially during first time intervals, a high priority code streamfrom a communication transmit node; receiving, substantially duringsecond time intervals, a low priority code stream from the communicationtransmit node; and receiving, substantially during the second timeintervals, an amplified high priority code stream from a relay node. 19.The computer-readable storage medium of claim 18, wherein the computingdevice is included in a communication receive node.
 20. Thecomputer-readable storage medium of claim 19, wherein the communicationreceive node comprises a mobile phone, a smartphone, or a laptopcomputer.
 21. The computer-readable storage medium of claim 18, whereinthe operations further comprise separating the amplified high prioritycode stream from the low priority code stream.
 22. The computer-readablestorage medium of claim 21, wherein separating the amplified highpriority code stream from the low priority code stream includesperforming a minimum mean squared error analysis of the received lowpriority code stream and amplified high priority code stream.
 23. Thecomputer-readable storage medium of claim 18, wherein the high prioritycode stream is configured to ensure basic communication service for acommunication receive node that receives the high priority code stream.24. The computer-readable storage medium of claim 23, wherein the lowpriority code stream is configured to enhance communication service forthe communication receive node.
 25. A radio communication systemcomprising: a communication transmit node configured to divide data intoa high priority code stream and a low priority code stream and totransmit the high priority and low priority code streams; a relay nodeconfigured to receive, amplify and forward the high priority codestream; and a communication receive node configured to: receive the highpriority code stream from the communication transmit node substantiallyduring first time intervals; receive the low priority code stream fromthe communication transmit node substantially during second timeintervals; and receive the amplified high priority code stream from therelay node substantially during the second time intervals.
 26. The radiocommunication system of claim 25, wherein a transmit power of thecommunication transmit node is about 35 dBm.
 27. The radio communicationsystem of claim 25, wherein a transmit power of the relay node is about20 dBm.
 28. The radio communication system of claim 25, wherein a signalto noise ratio in the radio communication system is about 18 dB.
 29. Theradio communication system of claim 25, wherein r is a maximumtransmission distance from the communication transmit node, furtherwherein a capacity of the communications system at a distance greaterthan about 0.75 r is in a range of 10% to 50% higher than in acommunications system lacking the relay node.
 30. The radiocommunication system of claim 29, wherein a distance between thecommunication transmit node and the relay node is about 0.5 r.
 31. Theradio communication system of claim 25, wherein the communicationtransmit node comprises a base station or an evolved Node B.
 32. Theradio communication system of claim 25, wherein the communicationreceive node comprises a mobile phone, a smartphone, or a laptopcomputer.